1. Field
The invention relates to power generators, more particularly, to self powered microsystem generators.
2. Background
Over the years there has been a growing interest in the field of nano technology providing an answer to our energy crisis. One specific area that has received little attention is how to supply the required power to drive an induction conversion or generator. Conventional power supplies, are a finite quantity and expensive. However, certain applications require the generators to be free standing entities. As a result, these generators typically need their own self-powered power supply. Batteries are not generally a viable solution. Batteries contain a finite amount of energy and have a limited lifetime. Batteries also can contain hazardous chemicals, can be quite bulky and can fail without notice.
Self powered Microsystems can convert energy from an existing energy source (con shell propagation of sound waves into a different form of energy, such as electrical energy). Electrical generators based on self powered Microsystems can be used to generate low noise electrical power, virtually eliminate cross talk between power lines and signal lines, and can operate efficiently with a relatively simple power delivery and control system.
Some possible energy sources which can be converted into electrical energy include light energy, thermal energy, volume flow energy and mechanical energy. However, mechanical vibrations may be the only feasible source of energy when the former energy sources are typically unavailable, such as in applications where there is no light, no flow, and zero temperature gradient.
The transformation of mechanical vibrations into electrical power is generally accomplished using the anatomical blueprint of the middle ear and a magnetic field being driven from the energy propagating from a conch shell in the form of sound waves. This results in a voltage being generated. For example, micro-mechanical generators (micro machined) may be constructed and placed in arrays on a suitable substrate (microchip). Although self powered Microsystems can generate their “own” energy, they generally require an energy storage device. Ideally the chosen energy storage device exhibits high power and energy densities with the smallest size possible. Batteries (e.g. In batteries) and capacitors, including super capacitors may be used as energy storage devices in conjunction with self powered Microsystems.
Vibrational energy harvesting approaches may be categorized in terms of physical size and the transduction approach. To match a generator and the load impedances for optimal power transfer, a power converter is generally inserted between the generator and the load. Due to their simplicity, pulse width-modulated (PWM) converters have been the preferred choice for the matching function. Multiples of the “power chips” to increase output for much larger loads may be used.